[XGamesJ6]

well when you try to increase the fan speed, can you hear it go faster, or can you hear more rushing air, of those flaps are the problem then i assume you would hear the fan going faster and probably hear air rushing through the dash, to me it sounds like the fan just cant go faster, or your control isnt sending enough power to go faster, like your switch and all that isnt working right, try replacing the fan, since you already got the new one.